$$TI = \frac{\text{Toxic dose}}{\text{Effective dose}}$$

Question 1

Which of the following best describes the structure of a typical virus?

Accepted Answer

A protein coat (capsid) enclosing nucleic acid, sometimes with an envelope

Question 2

Which step in the viral replication cycle involves the synthesis of viral genome and proteins?

Accepted Answer

Biosynthesis

Question 3

A bacterium is placed in a hypertonic solution. What process occurs, and what is the likely outcome?

Accepted Answer

Plasmolysis; the cell membrane shrinks away from the cell wall

Question 4

Which of the following is a correct formula for the therapeutic index (TI) of an antimicrobial drug?

Accepted Answer

$$TI = \frac{	ext{Toxic dose}}{	ext{Effective dose}}$$

Question 5

Which of the following best explains why prions are difficult to destroy using standard sterilization methods?

Accepted Answer

They lack nucleic acids and are resistant to heat and chemicals

Question 6

Which physical method is most effective for destroying bacterial endospores?

Accepted Answer

Autoclaving at $$121^\circ C$$ for 15 minutes

Question 7

A patient is infected with a virus that integrates its genome into the host DNA and can later cause cancer. Which virus is most likely responsible?

Accepted Answer

Human papillomavirus (HPV)

Question 8

Which of the following best describes the action of penicillin?

Accepted Answer

Inhibits cell wall synthesis by blocking peptidoglycan cross-linking

Question 9

Which microbial growth phase is characterized by a balance between cell division and cell death?

Accepted Answer

Stationary phase

Question 10

A microorganism that grows best at high salt concentrations is classified as a:

Accepted Answer

Halophile

Question 11

Which of the following is a mechanism by which antiviral drugs typically act?

Accepted Answer

Blocking viral replication inside host cells

Question 12

Which of the following best describes a facultative anaerobe?

Accepted Answer

Can grow with or without oxygen, but grows better with oxygen

Question 13

Which of the following is a correct description of a synergistic effect in antimicrobial therapy?

Accepted Answer

The combined effect of two drugs is greater than the sum of their individual effects

Question 14

Which of the following is NOT a target for antimicrobial drugs in bacteria?

Accepted Answer

Mitochondrial DNA replication

Question 15

Which of the following statements about the Kirby-Bauer disk diffusion test is correct?

Accepted Answer

It determines antibiotic susceptibility by measuring zones of inhibition

Question 16

Which of the following best describes the action of alcohols as disinfectants?

Accepted Answer

Disrupt cell membranes and denature proteins

Question 17

A virus that causes persistent infection by remaining latent in host cells is best exemplified by:

Accepted Answer

Herpes simplex virus (HSV)

Question 18

Which of the following is a correct definition of an obligate anaerobe?

Accepted Answer

Cannot grow in the presence of oxygen

Question 19

Which of the following is a common mechanism of antibiotic resistance?

Accepted Answer

Enzymatic destruction of the drug

Question 20

Which of the following best describes the stationary phase of the bacterial growth curve?

Accepted Answer

The rate of cell division equals the rate of cell death

Viruses, Microbial Growth, Control of Microbial Growth, and Antimicrobial Chemotherapy: Study Notes

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